Introduction: Physical endurance can be limited by muscle glycogen stores, in that glycogen depletion markedly reduces external work. During carbohydrate restriction, the liver synthesizes the ketone bodies, D-β-hydroxybutyrate, and acetoacetate from fatty acids. In animals and in the presence of glucose, D-β-hydroxybutyrate promotes insulin secretion and increases glycogen synthesis. Here we determined whether a dietary ketone ester, combined with plentiful glucose, can increase postexercise glycogen synthesis in human skeletal muscle.

Methods: After an interval-based glycogen depletion exercise protocol, 12 well-trained male athletes completed a randomized, three-arm, blinded crossover recovery study that consisted of consumption of either a taste-matched, zero-calorie control or a ketone monoester drink, followed by a 10-mM glucose clamp or saline infusion for 2 h. The three postexercise conditions were control drink then saline infusion, control drink then hyperglycemic clamp, or ketone ester drink then hyperglycemic clamp. Skeletal muscle glycogen content was determined in muscle biopsies of vastus lateralis taken before and after the 2-h clamps.

The high level of protein content reported in insects for food and feed is overestimated
Journal of Food Composition and Analysis Volume 62, September 2017, Pages 184-188

Highlights
• Insects have a great potential as future source for proteins.
• Total N is generally determined by Kjeldahl method.
• The N content in the cuticle errs the results.
• We propose to evaluate N derived from non-fibrous sources.
• It should result in an N-conversion factor similar among insects.

The potential of insects as a source of protein for future food and feed is widely admitted in the last couple years and is the object of numerous studies. The Kjeldahl method is widely used to quantify the crude protein content of insects which ranges from 8 to 70% of dry mass. This procedure evaluates the total concentration of Nitrogen (N), which is converted to protein by multiplying it by the nitrogen-to-protein conversion factor (N-factor) for meat (6.25).

Giving that the insect cuticle contents large amounts of fibrous chitin, a polysaccharide rich in N, and proteins tightly embedded in its matrix, and is not digested by humans or domesticated animals, using the Kjeldahl method overestimates the digestible protein content of insects. We propose to evaluate digetible nitrogen by quantifying N in the cuticle and sustraiting it from the total nitrogen content, and to calculate a new N-conversion factor which should be similar for all the insects species and their development stages.

Skeletal muscle samples were collected from twenty-one healthy males prior to and following 6 weeks of endurance training. Transmission electron microscopy was used for estimation of mitochondrial densities and profiles. Biochemical assays, western blotting and high resolution respirometry were applied to detect changes in specific mitochondrial functions.
Result

MitoVD increased with 55 ± 9% (P

< 0.001), whereas the number of mitochondrial profiles per area of skeletal muscle remained unchanged following training

. Citrate synthase activity (CS) increased (44 ± 12%, P < 0.001) however, there were no functional changes in oxidative phosphorylation capacity (OXPHOS, CI+IIP) or cytochrome c oxidase (COX) activity. Correlations were found between MitoVD and CS (P=0.01; r=0.58), OXPHOS, CI+CIIP (P=0.01; R=0.58) and COX (P=0.02; R=0.52) before training, after training a correlation was found between MitoVD and CS activity only (P=0.04; R=0.49). Intrinsic respiratory capacities decreased (P < 0.05) with training when respiration was normalized to MitoVD. This was not the case when normalized to CS activity although the percentage change was comparable.
Conclusions

MitoVD was increased by inducing mitochondrial enlargement rather than de novo biogenesis. CS activity may be appropriate to track training induced changes in MitoVD.

Mitochondrial derived peptides represent a new class of circulating signalling molecules. Humanin, the first member of this class, has been shown to have several metabolic effects such as reducing weight gain and visceral fat and increasing glucose stimulated insulin release. The discovery of several other new members such as MOTS-c and SHLP1-6, have further added to this group. These new peptides have also been found to affect metabolism with MOTS-c potently decreasing weight gain in mice on a high fat diet. In this review, we will cover the basic biology of this class of peptides and discuss the relevance to organismal metabolism.

The idea that increasing salt intake increases drinking and urine volume is widely accepted. We tested the hypothesis that an increase in salt intake of 6 g/d would change fluid balance in men living under ultra-long-term controlled conditions.

METHODS. Over the course of 2 separate space flight simulation studies of 105 and 205 days’ duration, we exposed 10 healthy men to 3 salt intake levels (12, 9, or 6 g/d). All other nutrients were maintained constant. We studied the effect of salt-driven changes in mineralocorticoid and glucocorticoid urinary excretion on day-to-day osmolyte and water balance.

RESULTS. A 6-g/d increase in salt intake increased urine osmolyte excretion, but reduced free-water clearance, indicating endogenous free water accrual by urine concentration. The resulting endogenous water surplus reduced fluid intake at the 12-g/d salt intake level. Across all 3 levels of salt intake, half-weekly and weekly rhythmical mineralocorticoid release promoted free water reabsorption via the renal concentration mechanism. Mineralocorticoid-coupled increases in free water reabsorption were counterbalanced by rhythmical glucocorticoid release, with excretion of endogenous osmolyte and water surplus by relative urine dilution. A 6-g/d increase in salt intake decreased the level of rhythmical mineralocorticoid release and elevated rhythmical glucocorticoid release. The projected effect of salt-driven hormone rhythm modulation corresponded well with the measured decrease in water intake and an increase in urine volume with surplus osmolyte excretion.

The majority of protein consumed in the diet is obtained from whole food sources that contain a mixture of macro- and micronutrients. Whereas the majority of research investigated the effect of isolated protein sources on protein metabolism, our aim was to assess the muscle anabolic potential of consuming a complete protein within its naturally occurring, nutrient dense food matrix during recovery from resistance exercise in young men.

The total amount of protein derived leucine that became available in circulation over the 300 min postprandial period was similar (P=0.53) between whole egg (75±2.3%) and egg white ingestion (77±1.7%).

We conclude that whole egg ingestion stimulates the muscle protein synthetic response more effectively than the consumption of isonitrogenous amounts of egg whites during recovery from resistance exercise in healthy young men. This effect is not attributed to divergent postprandial protein-derived amino acid availability, suggesting that some intrinsic factor within whole eggs and/or the divergent macronutrient profile may have modified the anabolic potential of this complete protein.